Mandela was right: the Foreign Language Effect

Mandela de Klerk

Nelson Mandela was an extraordinary man with an extraordinary talent for negotiation. He was also an outstanding public speaker. Among the many words of wisdom he left behind, there is this piece of advice for negotiations:

If you talk to a man in a language he understands, that goes to his head. If you talk to him in his language, that goes to his heart.”

So strongly did Mandela believe this, that he learned Afrikaans during his time imprisoned in Robben Island. The identification between Afrikaans and Apartheid was so strong that many activists were deeply offended when they heard Mandela speaking it to the white warders. But Mandela was right. So much so that his linguistic approach to negotiation might have given him an edge in his initial secret meetings with de Klerk. Mandela might have had a small advantage over his opponent when they negotiated in de Klerk’s native language. He unknowingly benefited from The Foreign Language Effect.

Would you make the same decisions in a foreign language as you would in your native one? Keysar, Hayakawa and Sun Gyu from the University of Chicago asked this question, and found out that the answer is “no”: our deeply rooted and irrational aversion to loss disappears when a problem is presented in a foreign language; we respond in a cooler, more rational way 1.

Our decisions are affected by a wide variety of seemingly irrelevant factors. One is our dislike to lose what we have, a dislike so strong that it wins over the pleasure of gaining something we did not have before. The Asian Disease problem illustrates this bias in our decision making. This is the situation we face:

Recently, a dangerous new disease has been going around. Without medicine, 600,000 people will die from it. In order to save these people, two types of medicine are being made.

Here is the problem framed in terms of losses:

If you choose Medicine A, 400,000 people will die. If you choose Medicine B, there is a 33.3% chance that no one will die and a 66.6% chance that 600,000 will die.

And here is the problem framed in terms of gains:

If you choose Medicine A, 200,000 people will be saved. If you choose Medicine B, there is a 33.3% chance that 600,000 people will be saved and a 66.6% chance that no one will be saved.

Which medicine do you choose?

Although the number of certain deaths is the same in both versions of the problem, people take the safer option (medicine A) more often when survivors are mentioned, and they take the riskier option (medicine B) when deaths are mentioned. So, when the same choice between A or B is presented in terms of losses (if you choose A, X people will die) or in terms of gains (if you choose A, X people will live), we are much more likely to choose B in the first case but A in the second 2.

Keysar and colleagues presented the Asian Problem to three groups of university students: (a) a group of 121 native speakers of English who had Japanese as a foreign language, which they had studied in school for an average of three years; (b) 144 native speakers of Korean who had English as a foreign language, which they had studied in school for about a decade; (c) 103 native speakers of English who were studying in Paris, had French as a foreign language, which they had studied previously in school for about six years. Participants were randomly assigned to either the native- or the foreign language condition, and to either the gain or the loss frame, and their task was to choose between the two medicines.

The results clearly showed the loss aversion effect at play when participants responded in their native language. But surprisingly, when they engaged in their foreign language, the loss aversion effect disappeared, and participants were now equally likely to choose the safer or the riskier option.

Foreign Language Effect
Credit: Keysar et al (2012)

The authors interpret this result as evidence that engaging in a foreign language increases psychological distance and promotes deliberation, mostly because of a reduction in emotional resonance. This does not mean that we become more or less risk seekers depending on the language in which the problem is presented, but rather that, whatever our decision, it is more affected by the way the problem is framed when presented in our native language than in a foreign one. That is to say, our emotions are not as strongly tied up in a foreign language, and we can think in a cooler, more detached and logical way.

This original finding has been pursued further by Costa and collaborators in a recent study of about 700 participants who were tested on different types of decision making problems3. In the first study, they replicated Keysar et al.’s (2012) results on loss aversion bias. In the other three studies, they explored whether the Foreign Language Effect was limited to emotion-related decision biases. What they found is that the Foreign Language Effect is pervasive in making our decisions less prone to intuitive biases. They also found that this effect only emerges when emotion is a key causal factor in the decision bias. When problems are not emotionally laden, the language effect disappears, which gives support to the idea that the foreign language effect is at least partially due to the emotionality produced by a given problem combined with a weaker emotional resonance of the foreign language.

So back to Mandela, and his negotiations with de Klerk in Afrikaans: Was the Apartheid an emotion laden problem for these two men? Yes, indeed it was, strongly so. And out of the two who was engaging in the cooler, more analytical and rational thinking mood? Mandela was, because he was not talking in his native language. A myriad of other factors at play, no doubt, but Madiba had the Foreign Language Effect on his side.


  1. Keysar, B., Hayakawa, S., & Sun Gyu, A. (2012). The foreign language effect: Thinking in a foreign tongue reduces decision biases. Psychological Science, 23, 661–668
  2. Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211(4481), 453–458
  3. Costa A., Foucart A., Arnon I., Aparici M. & Apesteguia J. (2014). “Piensa” twice: On the foreign language effect in decision making, Cognition, 130 (2) 236-254. DOI:


Post a comment

Itxaso ETxebarria LekandaItxaso ETxebarria Lekanda

Excellent article, very interesting. It gives us proof of what we sometimes suspect, that is, how our brains analyze language in a more surgical way when emotions are taken apart, when we have to construct the language we produce, and it no longer flows full of emotions (emotions attached to our mother language).
Personally, I would choose in both cases Medicine A, in the worst of possibilities, fewer lives would be lost.
What happens when we come across bilingual minds? Which of them is more emotional? Equally so?
Thank you for sharing knowledge

itziar laka

Thank you Itxaso, I was very glad to see your comment. You ask what happens regarding these two ways of thinking (fast and slow, as Kahneman puts it in his recent book) in different types of bilinguals, and the quick answer is we do not know yet. This discovery is relatively recent, and it will take time to go deep into it by exploring how bilinguals whose competence and frequency of use in their non-native language is high, or in simultaneous bilinguals with two native languages, or even in cases og language attrition, where the native language is not the dominant one and a later learned language becomes dominant…hopefully we will start having news in the near future but for now, these are frontier research questions.


I am a bilingual person who uses English, my second language, more often than my native language, Spanish. while reading the question I chose the first option save 200,000 lives. It is possible that once a person uses the language during situations with high emotional value such as communicating with a significant other the language obtains a higher emotional value which makes the person more prone to choosing the same answers one would with the native language.

itziar lakaitziar laka

Hi goldenromeo; your comment is very much to the point, and basically we still do not know. Once this first evidence is revealed, now we must proceed to know more. For instance, as you point out, what happens if one learned the second language because of love and has continued to use it daily, perhaps using the first language less? There are a myiriad scenarios we can imagine, and if we find enough people to test I am sure it will be done. On a case by case basis, though, it is hard to reach any conclusion…

Vasco Calais Pedro

Really good article. More and more, companies are understanding this fact and trying to engage their users and customers in their native languages. Given that over the next 5 years 70% of the world’s economic growth will come from developing countries, that means that there is a strong likelihood that English will not be that language. Learning a new Language is hard and unfortunately not everyone is as talented and visionary as Mr. Mandela. For the rest of us, I believe that if we can create seamless ways of translating communication, we could have both parties speak in their native language. Shameless plug for, we are trying to create a seamless translation process and make translation disappear. So that everyone can speak in their native language. Thank you for the article.


Actually most of the negotiations happened at Codesa in English, in neither the parties’ native tongues…

itziar lakaitziar laka

Hi Kobus, you are right about this, I only foudn out later, but in any event the main point still holds, although it benefited both parties when they talked in English.


It would be interesting to see the same studies conducted with bi-language people, people that have two or more languages like mothertongue.

Sandesh SalviSandesh Salvi

If we were to go into the question as to why that is so then here are some thoughts based on some analysis of human psychology: emotions are the results of our past experiences and conclusions stored as memory and most of our experiences that affect us are in the environment in which we spend most of our time in. There is a strong correlation between our native language and the the environment we spend most of our time in. So, the words in our native language invoke more emotions and also strong emotions than those in the foreign language affecting our decisions more emotionally.


Thank you for this article.
I am an italian native speaker and have learned French for 15 years as well as lived in french speaking countries. I have the feeling to feel myself more confortable speaking in my second-language, French, as I probably learned its grammar rules from zero with better support/follow-up by teachers, than the italian teachings I received since child. I imagine another cause is the interference with the regional dialect, less developed and less supported by the community, for which I unconsciously speak Freanch at ease rather than Italian.

Kurt MüllerKurt Müller

I found this quote in a number of places, though so far, I like your context better. Can you cite an original source?
Thank you.


Very good read stumbled upon whilst searching for Mandela quotes. This man was great in a sense that he thought tactically by learning Afrikaans he could reach his oppressors like no other. His legacy lives on.

6 Trackbacks

[…] ¿Tomaríamos las mismas decisiones en una lengua extranjera que en nuestra lengua materna? Keysar, Hayakawa y Sun Gyu de la Universidad de Chicago se hicieron esta pregunta, y descubrieron que la respuesta es «no»: nuestra arraigada e irracional aversión a la pérdida desaparece cuando se nos presenta un problema en una lengua extranjera; respondemos de manera más fría y racional 1. […]

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